自定义控件--CircleImageView（类似于QQ、微信圆形头像自定义控件）

现在基本上所有的需要用户注册的APP都有一个需要用户上传头像的需求，上传的头像基本都是类似于QQ、微信等社交应用圆形头像。最近，正在做的一 个社交应用多处需要用到这种圆形头像的处理，总不能每次都对图片做一些剪裁来实现圆形头像的处理，于是就想到了自定义一个控件来实现相应的效果。最后的效 果图如下：



1、自定义View（CircleImageView）

public class CircleImageView extends ImageView {

private static final ScaleType SCALE_TYPE = ScaleType.CENTER_CROP;
private static final Bitmap.Config BITMAP_CONFIG = Bitmap.Config.ARGB_8888;
private static final int COLORDRAWABLE_DIMENSION = 2;
private static final int DEFAULT_BORDER_WIDTH = 0;
private static final int DEFAULT_BORDER_COLOR = Color.BLACK;
private final RectF mDrawableRect = new RectF();
private final RectF mBorderRect = new RectF();

private final Matrix mShaderMatrix = new Matrix();
private final Paint mBitmapPaint = new Paint();
private final Paint mBorderPaint = new Paint();

private int mBorderColor = DEFAULT_BORDER_COLOR;
private int mBorderWidth = DEFAULT_BORDER_WIDTH;

private Bitmap mBitmap;
private BitmapShader mBitmapShader;
private int mBitmapWidth;
private int mBitmapHeight;

private float mDrawableRadius;
private float mBorderRadius;

private ColorFilter mColorFilter;

private boolean mReady;
private boolean mSetupPending;

public CircleImageView(Context context) {
super(context);

init();
}

public CircleImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

public CircleImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);

TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, 0);

mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_border_width, DEFAULT_BORDER_WIDTH);
mBorderColor = a.getColor(R.styleable.CircleImageView_border_color, DEFAULT_BORDER_COLOR);

a.recycle();

init();
}

private void init() {
super.setScaleType(SCALE_TYPE);
mReady = true;

if (mSetupPending) {
setup();
mSetupPending = false;
}
}

@Override
public ScaleType getScaleType() {
return SCALE_TYPE;
}

@Override
public void setScaleType(ScaleType scaleType) {
if (scaleType != SCALE_TYPE) {
throw new IllegalArgumentException(String.format("ScaleType %s not supported.", scaleType));
}
}

@Override
public void setAdjustViewBounds(boolean adjustViewBounds) {
if (adjustViewBounds) {
throw new IllegalArgumentException("adjustViewBounds not supported.");
}
}

@Override
protected void onDraw(Canvas canvas) {
if (getDrawable() == null) {
return;
}

canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius, mBitmapPaint);
if (mBorderWidth != 0) {
canvas.drawCircle(getWidth() / 2, getHeight() / 2, mBorderRadius, mBorderPaint);
}
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
setup();
}

public int getBorderColor() {
return mBorderColor;
}

public void setBorderColor(int borderColor) {
if (borderColor == mBorderColor) {
return;
}

mBorderColor = borderColor;
mBorderPaint.setColor(mBorderColor);
invalidate();
}

public int getBorderWidth() {
return mBorderWidth;
}

public void setBorderWidth(int borderWidth) {
if (borderWidth == mBorderWidth) {
return;
}

mBorderWidth = borderWidth;
setup();
}

@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
mBitmap = bm;
setup();
}

@Override
public void setImageDrawable(Drawable drawable) {
super.setImageDrawable(drawable);
mBitmap = getBitmapFromDrawable(drawable);
setup();
}

@Override
public void setImageResource(int resId) {
super.setImageResource(resId);
mBitmap = getBitmapFromDrawable(getDrawable());
setup();
}

@Override
public void setImageURI(Uri uri) {
super.setImageURI(uri);
mBitmap = getBitmapFromDrawable(getDrawable());
setup();
}

@Override
public void setColorFilter(ColorFilter cf) {
if (cf == mColorFilter) {
return;
}

mColorFilter = cf;
mBitmapPaint.setColorFilter(mColorFilter);
invalidate();
}

private Bitmap getBitmapFromDrawable(Drawable drawable) {
if (drawable == null) {
return null;
}

if (drawable instanceof BitmapDrawable) {
return ((BitmapDrawable) drawable).getBitmap();
}

try {
Bitmap bitmap;

if (drawable instanceof ColorDrawable) {
bitmap = Bitmap.createBitmap(COLORDRAWABLE_DIMENSION, COLORDRAWABLE_DIMENSION, BITMAP_CONFIG);
} else {
bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), BITMAP_CONFIG);
}

Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
drawable.draw(canvas);
return bitmap;
} catch (OutOfMemoryError e) {
return null;
}
}

private void setup() {
if (!mReady) {
mSetupPending = true;
return;
}

if (mBitmap == null) {
return;
}

mBitmapShader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);

mBitmapPaint.setAntiAlias(true);
mBitmapPaint.setShader(mBitmapShader);

mBorderPaint.setStyle(Paint.Style.STROKE);
mBorderPaint.setAntiAlias(true);
mBorderPaint.setColor(mBorderColor);
mBorderPaint.setStrokeWidth(mBorderWidth);

mBitmapHeight = mBitmap.getHeight();
mBitmapWidth = mBitmap.getWidth();

mBorderRect.set(0, 0, getWidth(), getHeight());
mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / 2, (mBorderRect.width() - mBorderWidth) / 2);

mDrawableRect.set(mBorderWidth, mBorderWidth, mBorderRect.width() - mBorderWidth, mBorderRect.height() - mBorderWidth);
mDrawableRadius = Math.min(mDrawableRect.height() / 2, mDrawableRect.width() / 2);

updateShaderMatrix();
invalidate();
}

private void updateShaderMatrix() {
float scale;
float dx = 0;
float dy = 0;

mShaderMatrix.set(null);

if (mBitmapWidth * mDrawableRect.height() > mDrawableRect.width() * mBitmapHeight) {
scale = mDrawableRect.height() / (float) mBitmapHeight;
dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f;
} else {
scale = mDrawableRect.width() / (float) mBitmapWidth;
dy = (mDrawableRect.height() - mBitmapHeight * scale) * 0.5f;
}

mShaderMatrix.setScale(scale, scale);
mShaderMatrix.postTranslate((int) (dx + 0.5f) + mBorderWidth, (int) (dy + 0.5f) + mBorderWidth);

mBitmapShader.setLocalMatrix(mShaderMatrix);
}

2、以上就是自定义View的全部实现过程，当我们需要使用这个功能是，只需要在XML布局文件中引用我们自定义的View即可

<com.tony.circleimageview.widget.CircleImageView
android:id="@+id/user_avatar"
android:layout_width="75dp"
android:layout_height="75dp"
android:src="@drawable/user_avatar_default"
/>

3、引入自定义View之后，我们就能实现上述效果图所示的效果了，只需几行代码就能实现圆形头像的功能了。有需要的可以直接拿过去使用了。

源码地址：https://github.com/tonycheng93/CircleImageView